Questions tagged [weather]
Weather means the atmospheric conditions, including wind, temperature and precipitation, in a specific area at a specific time.
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How can I calculate ambient air pressure from flight data?
I am playing around with data collected during a flight. I would like to find out the (real, not ISA) ambient air pressure for each data point, since it is not reported in the spread sheet containing ...
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1answer
91 views
How can air stability be predicted?
After several weeks of being grounded due to low clouds, I was looking forward to the cool air, clear skies, high pressure and light winds that arrived this morning as forecasted. However, there is an ...
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1answer
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What is the difference between the WSUSnn IDs used in convective SIGMETs?
When NOAA issues a convective SIGMET, it falls under one of three bulletin IDs: WSUS31, WSUS32, or WSUS33. Below are three examples from the current forecast.
WSUS31:
...
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116 views
What is the difference between mist and haze in terms of relative humidity?
I am an aviation meteorologist and I struggle to distinguish the two of them.
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Where can I listen online to live VOLMET broadcasts?
Are there sites that stream live VOLMET broadcasts? I need to listen to the format but haven't have the time to put together an amateur radio.
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2answers
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What do pilots landing on aircraft carriers do when the ship is not visible due to weather?
Say an aircraft takes off of a carrier to do a mission somewhere, and upon returning to the carrier the pilot comes to find that a thick layer of fog has formed just above the surface of the water in ...
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Does DA/DH refers to ceiling?
If airport is reporting FEW001 or SCT001 and RVR is above 600m, does it means that there will be no LVO because ceiling is defined as more than 4/8 and DA/DH will be more than 100ft because DA/DH is ...
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1answer
53 views
Are AWOS data open for commercial use? [closed]
I 've found out this great website where you can get historical AWOS weather data. I would like to use it for a commercial application but I don't find any data license. Do you know if the AWOS data ...
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1answer
66 views
Where is there an FAA source that states that squall lines are non-frontal?
There's a question in the FAA commercial question bank that indicates that squall lines are nonfrontal, and the reference for the question points to the Aviation Weather Advisory Circular.
The word, &...
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558 views
Can the “G” and “VRB” wind conditions be combined in METARs?
I have never seen the "VRB" (for wind direction variations < 60°; e.g. VRB12003KT) and "G" annotation (for gusts > 10KT wind speed difference; e.g. 12003GT30KT) being combined in a METAR.
Until ...
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1answer
51 views
How would a pilot apply the information found on a 500 Millibar Vorticity chart to a flight?
The U.S. Flight Service website has these weather products listed:
I have circled the 500 Millibar Vorticity Charts. I've been a pilot for 10+ years and have never heard mention of this chart by ...
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Is AMDAR a required system on aircraft?
I was intrigued by the assertion that COVID-19 depressing commercial aviation has lead to lower quality weather forecasting
The aircraft observations are a key piece in the jigsaw of national and ...
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Does a METAR report variable wind direction in a clockwise direction?
Does the convention for reporting variable wind direction always use a clockwise (nautical) sense?
For example, if the wind varies between 340 degrees and 10 degrees, assuming a clockwise sense the ...
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1answer
73 views
Is an area of localized reduced visibility considered to be a cloud?
If there an area containing visible moisture in an otherwise clear sky and that area of visible moisture is transparent is it considered a "thin cloud" or simply a "localized area of reduced ...
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1answer
106 views
What is an approved weather source for flying an instrument approach into an airport with no working ATIS?
What can you use as viable weather information landing at an airport with ATIS inoperative due to the tower being closed after hours? Let's assume the approach secondary weather source is also ...
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Who makes the call to start in terrible weather conditions?
I once headed to the airport during a huge thunderstorm with winds above 55 knots and massive rain and some small hail. At the airport, I saw that most flights were delayed or even canceled. To my ...
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Are helicopters impacted by fog more than airplanes?
With the crash of Kobe Bryant's helicopter, it seems a lot of focus has been placed on the helicopter flying low in fog (under "special VFR"). However, I've seen several suggestions that the ...
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How far can the sound of a sonic boom travel? [closed]
Are there conditions or distances from the plane to cloud to the observer in which a sonic boom from a plane is muted?
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Why and how do atmospheric properties sometimes vary from the ISA? [closed]
I'm curious as to why sometimes atmospheric properties don't match the ISA's. One reason I am considering is due to calibration discrepancies. By atmospheric properties I mean temperature, Density, ...
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Why did my LGA-ORD flight make an S-shaped turn round the time it was passing a storm?
On a recent United UA1709 flight into Chicago (hit by a heavy storm at the time), I felt a noticeable descent, combined with two wide banks around 1 hour before landing. Looking at the flight path, I ...
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1answer
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How do pilots avoid thunderstorms at night over the pacific en route to Australia where there is no radar? And what if a large front develops?
While there is some limited radar on board for pilots, we hear that there is no radar over the ocean which is why flight locations are estimated. As the distance between the United States and ...
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1answer
276 views
What to do if trapped on top VFR?
In the event that, despite his best efforts, a VFR-only pilot has gotten trapped on top of a solid cloud layer, what is(are) the safest course(s) of action?
For example, consider a long cross-country ...
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1answer
131 views
How to avoid getting trapped on top VFR?
This question addresses whether it is legal to fly VFR over-the-top.
One of the comments mentioned the difference between safety and legality, i.e. doing so may not be safe even if it is legal (in ...
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1answer
5k views
What fomula use for calculating pressure altitude?
I'm having some trouble making my calculations of pressure altitude match those in apps and text books.
I'm using the formula from Wikipedia:
(29.92 - altimeter setting) * 1000 + airport elevation ...
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1answer
485 views
What is the difference between ACARS and ADS-B?
What is the difference between ACARS and ADS-B?
For weather information in-flight or pre-flight which one is used?
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Does the coriolis force have an effect on the direction in which an aircraft travels?
Suppose an aircraft is flying from Kenya (which lies on the equator) to UK (which lies in the northern hemisphere). Does the Coriolis force veer the aircraft to the right? Do pilots have to correct ...
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1answer
382 views
Can you continue an ILS approach when weather falls below minimum?
If, after passing the final approach fix, weather deteriorates so that the reported values are now below required minima, is it allowed to continue the approach?
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1answer
131 views
What is the reasoning behind this question about the correct altitude to avoid clear icing?
This question has been killing me for a while and it's an original PPL question:
You are approaching to an airmass with a temperature of 6 C at
10000ft. Which altitude should you be in order to avoid ...
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1answer
165 views
Why jet stream is stronger in winter?
I notice in a website taling about jetstream
https://www.weather.gov/jetstream/jet
It says:
The winds blow from west to east in jet streams but the flow often shifts
to the north and south. ...
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4answers
117 views
Can airflow reverse over the flight surfaces of a uav in high wind conditions
Can airflow reverse over the wing of a uav in high tail winds and low forward airspeed i.e 25knt fwd airspeed in a 35 knt tailwind? What would be the overall effect on the elevator and rudder? I ...
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697 views
Approach when weather condition is below minimum
If airport weather condition is below minimum, but pilot report that flight weather condition is above minimum, Does controller can issue approach clearance to pilot?
If weather condition get worse ...
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3answers
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NEXRAD—why is it 2D?
If you paid attention to NEXRAD training, you know that the colors of pixels show the maximum activity at any altitude in that air column. (It’s a “composite” view.)
NEXRAD itself samples in three ...
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How did pilots avoid thunderstorms and related weather before “reliable” airborne weather radar was introduced on airliners?
How did airline and or mail pilots avoid hazardous weather especially at night before airborne weather radar systems were in use?
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Does an uncovered naval aircraft suffer any weathering affects?
This question is for WW2-era naval aircraft.
I noticed that some cruisers and battleships carried a couple seaplanes, launched by catapult and recovered with cranes.
Obviously these are unprotected ...
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2answers
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What does NSC mean in a METAR?
Here's a METAR:
SCEL 090000Z 15005KT 5000 HZ NSC 10/08 Q1020 NOSIG
What does NSC mean?
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3answers
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When do flights get cancelled due to fog?
When flights get cancelled due to fog, what triggers the cancellation? Fog is too thick, too wide-spread, blocks the view of tall buildings or other landmarks? Or is the problem the type of air ...
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What kind of input is used by NASA's TASAR?
I've found the Aviation SE to be a really interesting read so far, I'm excited to be here! I'm fairly new, but I'm also old!
What are the inputs for TASAR to crunch flight path optimization? Is it ...
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What the weather condition can affect for flight? [closed]
What is the most disturbing weather conditions for flight?
On another word: what more dangerous for takeoff/landing: wind, precipitation or something else?
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3answers
154 views
What does the future of the weather radars look like?
Planes had weather radars for a long time (Dassault Falcon and Learjet35A) which was useful since you either had to ask ATC, listen the ATIS frequency or ask the flight advisory before flight planning ...
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What is an “all-weather” aircraft?
I've read a few times that such-and-such a plane is an "all-weather" aircraft, for example:
The McDonnell Douglas F/A-18 Hornet is a twin-engine, supersonic, all-weather, carrier-capable, multirole ...
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What are the duration of TAFs?
TAFs (terminal aerodrome forecast) have different durations. Some forecasts 30 hours into the future while others forecasts only 24 hours.
But what is the shortest and longest TAFs? and how often are ...
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2answers
548 views
What is the relation between clouds and radar effectiveness?
Recently, India's prime minister Narendra Modi commented on how cloudy weather can help a fighter jet escape from radar. Is there any technical reasoning to back these comments?
Here is the quote ...
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775 views
For an airport to be designated as an IFR alternate, does it have to have a TAF?
For an airport to be designated as an IFR alternate, does it have to have a terminal aerodrome forecast at the alternate airport to confirm that the forecast 600-2 and 800-2 will be in place at the ...
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1answer
256 views
Why is a small amount of smooth ice over the top of the wing more dangerous than an accumulation on the leading edge?
According to a Gleim study guide,
"Generally speaking, smooth ice on top of the wing is more dangerous than heavy accumulated icing on the leading edge."
Is this true? If this is true, why?
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Are there more accidents in winter months, and if so, why?
I was watching The Flight Channel videos and have noticed that the accidents seem to happen more often in winter months (for the Northern Hemisphere). Are there some statistics to back this claim?
It ...
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1answer
878 views
What is the meaning of R88/70D in this METAR from Ashgabat International airport?
The following METAR is from Ashgabat airport (UTAA)
UTAA 071300Z 13006KT 9999 FEW050CB BKN050 BKN100 15/06 Q1013 R88/70D
NOSIG
What does R88/70D mean, I couldn't find any references?
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1answer
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Is navigation around thunderheads done at the pilot's discretion?
It's my understanding that if a pilot is flying over an ocean or otherwise uncontrolled airspace and they encounter a cumulonimbus, they navigate around it at their discretion.
How does this happen ...
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What is the purpose of including sea level pressure and temperature in a METAR?
In a METAR such as this one:
KGOK 161553Z AUTO 18011KT 4SM BR OVC007 07/05 A3011 RMK AO2 SLP201
T00670050
Translated to:
Jan 16, 1553Z, Automated. Mist, Wind from 180° at 11 knots, 4 statute
...
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How is the effect of wind on arrival time handled?
If a commercial plane encounters strong tailwinds, would the pilots set the autopilot for a fixed arrival time (if that is possible), or would it be ok to arrive way ahead of schedule?
I imagine ...
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1answer
140 views
When is a high pressure system associated with IFR/MVFR conditions?
So I've read that typically high pressure systems bring good weather and clear skies. However, for the current high pressure system we're experiencing in central USA, we're having quite a bit of IFR/...
